rsay

i'm new to 1/2A but will be getting my feet wet with a Thunder Tiger GP07 on the way.

one question though, will this engine last forever? i've read in many of the posts here that the owners of cox engines and such have had their engines for almost a decade but they still work. does this hold true for the GP07?

i'll be using only methanol and castor oil for it, no nitro.

please pitch in any experiences you've had with this engine.

jessiej

I have two of the TT .07s. The inevitable comparison is with the Norvel .074. The Norvel is substantially more powerful than the TT, but the TT .07 is a very pleasant, user friendly engine.

I have no experience running 1/2a engines with no nitro. Normally I expect smaller engines to require more nitro. I use 15% in my GP .07.

Will it last forever? Of course not. Given proper care and not run overly lean it will last as long as a Cox or any similar engine.

jess

propbuster

My Feedback: (1)

It's my understanding that small engines need a high % of nitro due to the fact that they run cooler than the bigger guys. I don't have any experience with the TT.07 but I use 25% nitro and castor with my Cox engines. A couple of them are over 20 yrs old and still run fine.

BMatthews

Welcome to RCU rsay.

You may find that the TT 07 runs better if you can get some nitro but if not then increasing the compression ratio a little will help. Not sure how you could do that since I don't have a TT 07 to look at. Otherwise straight alcohal and oil isn't going to make much power.

Life span is dependent on many factors. If the engines are run in a clean environment they can last for years. But dust and grit blowing up and being ingested can lead to scored bearings and cylinders that reduce the lifespan to a few short months in extreme cases.

If long life is important and your flying area is sandy or dusty then a stand to lift the model up will help a lot. Also a filter of nylong stocking material or similar fine weave fabric can help prevent some particles getting into the engine. For extreme cases the air filters used on the nitro car engines can be adapted.

Bipe Flyer

I've run my TT .07 on 15% to 25% Nitro with no problems. In fact, I switched to 15% Omega because the 25% Nitro fuel that I use has 20% castor and was putting out the plug when flying inverted. It is a good running engine but, as jessiej mentions, doesn't have the power of a Norvel .074. There are no head gaskets, so there is no easy way of increasing the compression that I can see.

Mine has a fair amount of time on it (2 planes over 3 years) and it looks pretty good, so I'd say that it should last a long time with proper care.

Here are a couple of clips of mine in a 17.5oz Ugly Stick, which it flew nicely. You might have to "right click, save as".

http://donatelli.net/12astik/12AStik-to.mpg
http://donatelli.net/12astik/12AStikLdg.mpg

rsay

thanks all.

bmatthews, i will keep your advice in mind. a lot of flyers here (in my area) are willing to help me out but useful info from folks overseas will provide more help as well.
i'll post an "exploded view" of the GP 07 so you can maybe check if it has the compression ratio you speak of. got it from their catalog from acehobby website.

another question though, i was planning to use this engine on gws planes (and ACE simple series planes if i can find any in my country) but after seeing the wattage arf's, i was wondering if this engine could power them up. they use 480 size electric motors and run on direct drive.

what is the equivalent of this engine to electric motors anyway?

sorry for the many questions but i've found this forum to be very helpful when it comes to 1/2A when compared to the "other" forum where i'm often asked "why would you wanna do that?" whenever i ask about E-to-GLOW conversions

rsay

looks like bipeflyer beat me to the picture and the info.

bipeflyer, i've already downloaded those clips a few days ago. kept watching it over and over. kinda got me hypnotized and excited about my engine.

i've also downloaded your 1/2A trainer and plan to have one built by the "builder" here. depends on how much he'd charge, though.

is nitro really necessary? it's so expensive here. the cost of two cans is equal to an engine already. besides, i don't plan on doing 3d. just some scale flying and mild aerobatics.

Bipe Flyer

A friend of mine has a ACE Simple 400 with a 480 in it running on 3 cell LiPolys and I'd say that the TT .07 has a fair amount more power.

If you can get the engine to run on no Nitro, then great. Nitro may be expensive, but you'll only be burning 2oz of fuel per flight.

The TT .07 should be perfect for the LST trainer.

flyinrog

My Feedback: (1)

Bipe I just looked at my .07 and its filthy inside!is yours a glow head,hard to tell on the pic,,mine has a glow plug in it...the piston head is absolutly black,,I unscrewed the backplate and it smells like 10 year old gas in there,,needless to say I have never ran or really looked at this engine..Rog

Bipe Flyer

It is the stock head button with an OS #8 plug.
I was kind of surprised at how clean mine is when I took the head off. Every other engine (Norvel, OS, etc.) that I've looked at has at least some discoloration or build up on the cylinder or the plug.

John A

Mine came from the factory without a head gasket. When I ran it for the first time I had bubbles coming out the pin in the rear of the engine that lines up the piston liner. The mixture was very erratic. If I had not noticed the bubbles I would have thought it just needed breaking in. I tightened and loosened the head a couple times, then again after running it proved no improvement. I called TT and found out they are supposed to come with one and they dropped one in the mail for me. I'm surprised yours ran that well without it. I'm surprised, too, that you are using a number 8. I have a short plug in there now, might have to give that a try.

Bipe Flyer

Oops, I was wrong. There IS a head gasket, it is aluminum and I thought it was part of the "button".

The OS #8 seemed like the perfect length to me, so I used it.

flyinrog

My Feedback: (1)

Not one on mine anywhere,,maybe it was run rich to compensate,hence the black piston?

meowy84

Hey Bipe, I thought you only flew Bipes. A very nice landing though (in my newbie opinion). Also gotta love B.C.......and not only for the bud! heh heh *cough*toke*

jessiej

[The OS #8 seemed like the perfect length to me, so I used it. ]

I am currently running a Fireball in mine. I think it is the same length as the OS#8.

jess

jessiej

[The OS #8 seemed like the perfect length to me, so I used it. ]

I am currently running a Fireball in mine. I think it is the same length as the OS#8.

A Miracle Plug or idle bar plug will hit the piston, though. (I was very careful when I checked)

jess

Richard Say

rsay,
My name is Richard Say. I just noticed your user name is rsay. Where I live, the name (Say)is rare. I couldn't ignore the possibilities.

BrykMantis

Bipe Flyer,

What kind of fuel and prop (size and make) are you using in that Ugly Stick? I've got the GP-07 in my TT Scooter 007 and it barely gets out of its own way!

Also, does your tightened prop and nut have a little play in it on the shaft? (in and out ) Mine does and I wonder if that is bad.

Right now I get about 11,000 rpm on a 7x4 using 15% nitro. Seems a little weak.

Thanks

Bipe Flyer

I never tached it, but I used an APC 7X3 in the video clips.

jessiej

[What kind of fuel and prop (size and make) are you using in that Ugly Stick? I've got the GP-07 in my TT Scooter 007 and it barely gets out of its own way! ]

OK, confession time. I too have a Scooter. My only rtf. My only excuse for having in my possession a RTF is that I had been badly injured in an automobile accident and thus unable to complete the 1/2a project on my bench at the time.

That being said, I was impressed enough enough with the TT.07 t purchase another. While the performance does not approach my Norvel .074, it is so user friendly and so pretty that I Purchased another as yet unrun example.

I also have been so impressed by my Norvell .074 that I feel compelled to build something for it. I have a virvinal Arden Glo .09. How do you suppose a model designed for that Arden would perform with the Norvel?

jess

BrykMantis

What kind of Fuel were you using? (Nitro% and Manufacturer)

Also, does your tightened prop and nut have a little play in it on the shaft? (in and out ) Mine does and I wonder if that is bad.

Thanks

ZAGNUT

My Feedback: (1)

0% nitro on the small engines can be tricky but here's a couple of ideas:

find a hot plug, OS should have one and since they are short they shouldn't be a problem.

add some acetone to the fuel. 5% is the norm but you can experiment if you like. it's a cheap way of adding a little heat to the combustion

toss the gasket and lap the head to the cylinder with toothpaste, just make sure you still have a bit of clearance between the piston and squish band

castor, castor, castor...especially if you want the engine to last forever...


dave

mclintock

My Feedback: (3)

.. Both of mine do- makes a pretty loud clack when I pull in and out on the prop when the engine is mounted in the scooter, the airframe acts as a soundboard.. I don't think it is anything to worry about..

BrykMantis

Clint,

What prop (size and manufacturer ) do you use on your Scooter with the TT.07? I use a 7x4 with 15% fuel and it can barely get out of its own way. I know its not a combat plane but, I wouldn't mind a little more authority.

Thank You

Casabryk

mclintock

My Feedback: (3)

Casabryk,

Due to slackness, a baby, a 100+year old house to fix, and horrid boston flight conditions- I have yet to actually run my .07 and fly my scooter. I just read the manual every now and then. The prop that came with the plane is what I was going to use, that or a 6-4 kaman, the soft yellow ones from hobby lobby. I don't expect the greatest performance when I do fly it, with such a long wing span vs such a small motor.

One help for the scooter, that I have already changed on mine, is replacement of those huge servos with some more reasonable ones.
Also, the battery cage and four AA pack is overkill, this plane should do fine with an 4xAAA battery pack. A fair amount of weight in that huge stock radio (assuming you got a scooter with the ace radio in it)..

clint